SAN
FRANCISCO ? The technology and tools already exist to allow people and robots
to repair and refuel satellites in orbit. What is lacking is the recognition of
that capability by senior government officials and a business model to enable
commercial companies to profit from the enterprise, according to government and
industry officials attending a workshop March 24-26 sponsored by the NASA
Goddard Space Flight Center and held at the University of Maryland University
College in Adelphi, Md.

"It's
pretty clear," said Frank Cepollina, NASA deputy
associate director in the space
service capabilities office at NASA Goddard in Greenbelt, Md. "The
time for study is over. We have now got to move forward."

The workshop
was one step in a space agency campaign to demonstrate that a wide range of
satellite repair, refueling and maintenance activities can be performed by
human and robotic missions. NASA is conducting a study to determine the
feasibility and cost of in-orbit
satellite servicing. The results of that study are scheduled to be
delivered to Congress in September, said Cepollina, NASA's
lead engineer for Hubble Space Telescope repair missions.

NASA's
long-term goal is to prove that satellites can be serviced in orbit, conduct a
pathfinder mission to prove the concept and then transfer the technology to the
commercial sector, Cepollina said.

NASA plans
to demonstrate in-orbit satellite refueling at the international space station
with the help of Dextre, the two-armed Canadian robot. In an experiment scheduled
to be conducted in the next six to 12 months, Dextre
will be equipped with special tools on the end of its arms to cut through a
satellite's exterior, insulation and wiring, hook up a hose and pump hydrazine
into the satellite. For the experiment, NASA will be relying on a simulated
satellite, being built by NASA Goddard engineers and scheduled to be completed
in October. The mock spacecraft ? essentially just the back end of a satellite
? will be bolted to an Express Logistics Carrier, a platform attached to the
space station's exterior. Once the simulated spacecraft and tools are
completed, the equipment will be sent to the space station.

"The
simulated spacecraft is fully wrapped, like a spacecraft in geosynchronous or
low Earth orbit," Cepollina said. The experiment
will be directed by astronauts on the ground, probably located at Johnson Space
Center in Houston, and will not involve any of the space station crew.
"The fundamental objective is to prove that you don't have to design your
satellites to be refueled on orbit," Cepollina
said. "You can refuel existing fleets."

Following
this experiment, NASA plans to demonstrate the work can be done autonomously, Cepollina said. That demonstration will be important to
show that satellites traveling 14,000 kilometers from Earth in geosynchronous
orbit also can be refueled
and repaired. "We are trying to develop the dexterity of robots to fix
spacecraft so they can continue to do their jobs, Cepollina
said. "You would never buy a car that was not repairable, why should we
buy a satellite that's not?"

During the
workshop, participants reported on in-orbit servicing and refueling projects
conducted by private industry, the U.S. Naval Research Laboratory, the U.S.
Defense Advanced Research Projects Agency (DARPA) and NASA Goddard. Speakers
also cited projects under way in Germany and Canada. In February, the German
space agency DLR awarded a contract to OHB Technology of Bremen, Germany, to
act as the prime contractor for the detailed design phase of the German Orbital
Servicing Mission, a program that includes robotic technology to repair, refuel
and de-orbit satellites.

Canada's
MacDonald Dettwiler and Associates (MDA) Corp. is
preparing to launch a mission in approximately three years to deliver 2,000
kilograms of fuel to an orbiting geostationary satellite. That work is being
done for a customer that the company is not identifying. "We will validate
the whole idea of on-orbit servicing," said John Lymer,
MDA chief robotics engineer. "We will show that it is not only useful to
the client, but that the service provider can make money as well." In
order to see a profit, however, MDA must keep program costs as low as possible
by relying on existing flight technology, Lymer said.

In fact, the
only way companies can make money servicing
satellites in orbit is to spread the cost of the missions and associated
technology across multiple jobs, said Glen Henshaw, a
roboticist at the Naval Research Laboratory in
Washington. "It's not a technology problem," he added. "We have
the technology to establish all of these capabilities today, but the technology
can help us close the business case."

Henshaw compared the
business of satellite servicing with that of automobile servicing. An
automobile's value and the way it is used helps to determine the types of
repairs a customer is willing to make. Few companies would rebuild a Toyota
engine, but mechanics will perform that work to fix an extremely valuable
automobile such as a Maserati.

By
comparison, NASA is likely to pay a far higher price to repair and refuel
billion-dollar space telescopes than companies would be willing to pay to fix
communications satellites, Henshaw said. Still, other
workshop participants said that the sheer quantity and value of government and
commercial satellites in orbit indicate that there is an enormous market for in-orbit
repair and maintenance activities.

To bring
down the cost of those missions and make them more profitable, companies are
developing a variety of technologies including advanced propulsion systems,
improved fault detection programs, sophisticated sensors and equipment designed
to ease the process of transferring cryogenic fuel, according to workshop
participants.

Another
hurdle to clear before in-orbit servicing becomes routine is to convince senior
government and industry officials that in-orbit servicing can be done safely
and effectively, said U.S. Air Force Lt. Col. Fred Kennedy. Kennedy was the
program manager for DARPA's Orbital
Express program, a successful 2007 demonstration of autonomous satellite
refueling and maintenance.

"The
technology can help with that," Henshaw said.
"We can beat down some of the perceived risk."

However,
some decision-makers will be skeptical until they see concrete demonstrations
of in-orbit satellite servicing. "We should just go do it," Henshaw said. "Until we do it, nobody is going to
believe we can do it."